public class BookSystem {
    public static void main(String[] args) {
        // 1. 初始化图书数据
        // 图书编号数组
        String[] bookIds = {"B001", "B002", "B003", "B004", "B005"};
        // 图书名称数组
        String[] bookNames = {"Java编程基础", "数据结构与算法", "Python入门", "数据库原理", "计算机网络"};
        // 图书借阅状态数组，true:已借出，false:未借出
        boolean[] isBorrowed = {true, false, true, false, false};

        // 2. 输出所有未借出的图书
        System.out.println("当前可借阅的图书：");
        int availableCount = 0;
        for (int i = 0; i < bookIds.length; i++) {
            if (!isBorrowed[i]) { // 未借出
                System.out.println(bookIds[i] + "：" + bookNames[i]);
                availableCount++;
            }
        }
        System.out.println("可借阅图书总数：" + availableCount);

        // 3. 处理图书归还（B001归还）
        String returnBookId = "B001";
        for (int i = 0; i < bookIds.length; i++) {
            if (bookIds[i].equals(returnBookId)) {
                isBorrowed[i] = false;
                System.out.println("\n" + returnBookId + "已归还");
                break;
            }
        }

        // 4. 再次统计可借阅图书数量
        availableCount = 0;
        for (boolean borrowed : isBorrowed) {
            if (!borrowed) availableCount++;
        }
        System.out.println("归还后可借阅图书总数：" + availableCount);
    }
}